US4919736A - Aluminum alloy for abrasion resistant die castings - Google Patents
Aluminum alloy for abrasion resistant die castings Download PDFInfo
- Publication number
- US4919736A US4919736A US07/226,011 US22601188A US4919736A US 4919736 A US4919736 A US 4919736A US 22601188 A US22601188 A US 22601188A US 4919736 A US4919736 A US 4919736A
- Authority
- US
- United States
- Prior art keywords
- alloy
- less
- weight
- aluminum alloy
- addition
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000005299 abrasion Methods 0.000 title claims abstract description 27
- 229910000838 Al alloy Inorganic materials 0.000 title claims abstract description 10
- 238000004512 die casting Methods 0.000 title abstract description 7
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 64
- 239000000956 alloy Substances 0.000 claims abstract description 64
- 239000013078 crystal Substances 0.000 claims abstract description 20
- 229910052802 copper Inorganic materials 0.000 claims abstract description 14
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 11
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 10
- 229910052742 iron Inorganic materials 0.000 claims abstract description 9
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 8
- 229910018643 Mn—Si Inorganic materials 0.000 claims abstract description 7
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 239000006104 solid solution Substances 0.000 claims abstract description 7
- 150000001875 compounds Chemical class 0.000 claims abstract description 6
- 239000011159 matrix material Substances 0.000 claims abstract description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims description 6
- 239000010949 copper Substances 0.000 description 21
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 13
- 238000012360 testing method Methods 0.000 description 13
- 239000011777 magnesium Substances 0.000 description 10
- 239000011572 manganese Substances 0.000 description 10
- 229910000765 intermetallic Inorganic materials 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 238000005266 casting Methods 0.000 description 8
- 238000004453 electron probe microanalysis Methods 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 239000008187 granular material Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 4
- 230000002411 adverse Effects 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- 239000011701 zinc Substances 0.000 description 4
- 229910008302 Si—Fe—Mn Inorganic materials 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000010687 lubricating oil Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 238000009864 tensile test Methods 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910018563 CuAl2 Inorganic materials 0.000 description 1
- 229910001366 Hypereutectic aluminum Inorganic materials 0.000 description 1
- 229910019641 Mg2 Si Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000000635 electron micrograph Methods 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 238000007542 hardness measurement Methods 0.000 description 1
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
- C22C21/02—Alloys based on aluminium with silicon as the next major constituent
Definitions
- This invention relates to an aluminum alloy for abrasion resistant die casting. More particularly, it relates to an aluminum alloy with excellent abrasion resistance and mechanical properties.
- Hypereutectic aluminum alloys containing, by weight, from 14 to 25% silicon have been widely used in sliding parts as die casting alloys having excellent abrasion resistance.
- 390 Alloy comprising by weight 16.0 to 18.0% Silicon(Si), 4.0 to 5.0% Copper(Cu), 0.45 to 0.65% Magnesium(Mg), 0.1% or less Zinc(Zn), 0.6 to 1.1% Iron(Fe), 0.1% or less Manganese(Mn), 0.02% or less Titanium(Ti), trace of Phosphorous(P), and the remainder being Aluminum(Al), is so highly resistant against abrasion that it is used as an aluminum engine block free from cast iron liners.
- JP-B as used herein means an "examined Japanese patent publication”
- Si silicon
- Cu 0.5% or less Mg, 1.0% or less Zn, 1.3% or less Fe, 0.5% or less Mn, 0.05 to 0.1% P, 0.5% or less Nickel(Ni), 0.3% or less Tin(Sn), and the remainder being Al
- P 0.5% or less Nickel(Ni), 0.3% or less Tin(Sn)
- the remainder being Al is 390-Alloy based, in which the alloy's machinability is improved without considerably damaging its original abrasion resistance.
- the alloy is used in a broad field as housings of door closers, etc.
- JP-A-No. 60-2643 The alloy disclosed in JP-A-No. 60-2643 (the term "JP-A" as used herein means a published unexamined Japanese patent application) containing by weight, 5.0 to 22.5% Si, 5.5 to 10.5% Cu, 0.8 to 1.5% Fe, 0.85 to 1.5% Mg, 0.002 to 0.025% P, and the remainder being Al and inevitable impurities, is an aluminum alloy for die castings suitably used for sliding parts which work satisfactorily when used with either high- or low-viscosity lubricating oils.
- the inventors have studied a solution for aforesaid problems and developed an aluminum alloy for abrasion resistant die casting comprising by weight, 6.0 to 9.0% Cu, 0.5 to 2.0% Mn, 1.6 to 3.0% Fe, 3% or less Mg, together with 13.5 to 20.0% Si, 0.5% or less Ni, inevitable impurities and the remainder being Al, with the hardness of the new alloy being increased by crystallizing out primary Si crystals and Al-Fe-Mn-Si compounds, and by forming a solid solution with Cu and Mg in the alloy's matrix.
- FIG. 1 shows the test pieces prepared with the alloy of the present invention.
- FIG. 2 shows micrographs, at 5,000 times magnification of the cast structures of the alloys; "a” is for the alloy of the present invention, “b” is for the 390 Alloy, and “c” is the alloy disclosed in JP-B-No. 53-37810.
- FIG. 3 shows the results of planar analyses by EPMA (Electron Probe Micro Analysis) for primary Si crystals and Al-Fe-Mn-Si quaternary intermetallic compounds at 1,500 times magnification, wherein a is the SEM (Seanning Electron Micrograph) image, and b, c, d, and e show the results with Al-K ⁇ , Fe-K ⁇ , Mn-K ⁇ and Si-K ⁇ radiations, respectively.
- EPMA Electro Probe Micro Analysis
- the alloy composition of the present invention contains from 13.5 to 20.0% by weight of Si to give excellent castability and abrasion resistance. If the amount of Si is less than 13.5% by weight, the product would be deficient in primary Si crystals, and abrasion resistance would not be improved. If the addition is in excess of 20% by weight, the addition would leads to a rise in casting temperature, and the machinability of the alloy would therefore be adversely affected.
- the preferred range for Si is 15.2 to 17.5% by weight.
- Copper forms a solid solution with Al to enhance the strength and improve the high temperature strength of the alloy.
- the addition of copper is desirably 5.9% by weight or more, however, addition in excess of 9.0% gives no apparent improvement in strength but adversely lowers the castability. Copper addition by weight is, therefore, desirably in the range from 6.0 to 9.0%, most preferably from 0.0 to 7.1%.
- Addition of manganese leads to the formation of a massive Al-Fe-Mn-Si quaternary intermetallic compound having a hardness Hv of about 960. Though the hardness of the compound is lower than that of Si (Hv 1,300), it contributes to the improvement of abrasion resistance. Too high an amount of Mn addition, on the other hand, forms a sludge during dissolution which settles on the bottom of the crucible. The amount of Mn addition by weight, therefore, should be 2% or less, preferably from 0.5 to 2%, most preferably 1.1 to 1.7%.
- Iron avoids adhesion to a metal mould and also forms an Al-Fe-Mn-Si intermetallic compound which improves abrasion resistance. Iron should be added in an amount of 1.6% by weight or more to sufficiently give the aforesaid intermetallic compound. Addition of Fe in excess, however, adversely affects mechanical properties.
- the Fe content is desirably less than 3.0% by weight. Most preferably Fe addition is from 1.7 to 2.8% by weight.
- Mg addition increases mechanical strength and hardens the alloy per se. However, too large an addition of magnesium adversely affects melt fluidity, and brittleness results. An addition of 3% by weight or less of magnesium gives satisfactory effects. Preferably Mg addition is from 1.0 to 2.2% by weight.
- Nickel addition not only increases high temperature strength but also hardness. However, addition decreases corrosion resistance. Nickel addition is, desirably, 0.5% by weight or less, more preferably 0.1% by weight or less.
- Zinc addition of 1.0% or less by weight gives satisfactory results.
- Preferred Zn addition is 0.1% by weight or less.
- Tin is present as an inevitable impurity, but its content should be less than 0.3%.
- Phosphorus is effective to make fine Si crystals. Fine Si crystals give good machinability and also improve mechanical properties. An addition of less than 0.001% by weight of phosphorus is insufficient to give fine crystals. An addition of more than 0.1% by weight, however, has no effect on the primary crystal size of Si.
- the addition of P is therefrom maintained in the range from 0.001 to 0.1% by weight. The preferred range for P addition is from 0.05 to 0/1% by weight.
- the experiments were performed on test pieces shown in FIG. 1 having the alloy compositions as listed in Table 1.
- a 90-ton die casting machine was used for casting. Casting conditions were as follows: temperature of 720° to 730° C., casting pressure of 760 kgf/cm 2 , plunger tip speed of 1.35 to 1.40 m/sec, mold temperature of 120° to 140° C., and mold release time of 4 sec.
- Each alloy composition of the present invention showed excellent castability free from run deficiency, scuffing, and seizure.
- the Cu content is 10%, the run is more or less damaged.
- Casting structures for the die cast alloy of the present invention, 390 Alloy, and the alloy disclosed in JP-B-No. 53-37810 are given in FIG. 2.
- the test pieces were etched with an aqueous 5% HF solution.
- the casting structures of 390 Alloy and the alloy of JP-B-No. 53-37810 comprise primary Si crystals, dendritic and eutectic crystals of Si, and intermetallic compounds such as CuAl 2 and Mg 2 Si.
- dark gray granules are the primary Si crystals. The large granules deteriorate the machinability.
- the granules are reduced in size so that the machinability is improved, however, the amount of the primary Si granules is decreased so that the hardness is lowered.
- the cast structure of the alloy of the present invention exhibits additional crystal deposition of Al-Si-Fe-Mn quaternary intermetallic compound. Light gray granules observed in the micrograph correspond to above crystals.
- FIG. 3 shows the EPMA result for the Al-Si-Fe-Mn quaternary intermetallic compound.
- the Scanning Electron Micrograph given in FIG. 3a reveals a mass nearly hexagonal in shape to be present at a lower left side thereof.
- EPMA analysis using Al-K ⁇ radiation indicates that the massive part is low in Al, but is high in Fe and Mn as observed in analyses using Fe-K ⁇ (FIG. 3c) and Mn-K ⁇ (FIG. 3d).
- the analysis using Si-K ⁇ (FIG. 3e) shows that the massive part is slightly low in Si. The massive part is therefore identified as an Al-Si-Fe-Mn quaternary intermetallic compound.
- FIG. 3d indicates an extremely high Si concentration at the upper right of the micrograph.
- the test pieces shown in FIG. 1 were subjected to tensile test at room temperature using a 10-ton tensile tester. The speed was 5 mm/sec. In both the tensile strength and the 0.2% yield strength, the higher the Cu content, the larger the result obtained. Both values keep approximately constant values at Cu contents of 6 to 7% or more.
- the tensile strength and the 0.2% yield strength of the alloy of the present invention are approximately 10% higher and 20% higher respectively than that of 330 Alloy or the alloy of JP-B-No. 53-37810. Elongation increases more or less with the addition of Mn, and is low when the Cu content is high. The elongation is the least for the alloy containing about 3% by weight of Cu.
- Hardness was measured on the surface of a rectangular test piece as shown in FIG. 1, being polished as far as about 1 mm in depth. A Rockwell hardness testing machine was employed and the measurement was performed based on the B scale. It was harder for a higher Cu content, and reached approximately a constant value in the range from 6 to 9% by weight of Cu.
- the hardness of the alloy of the present invention is about 10% higher than the conventional 390 Alloy, and about 20% higher than the alloy of JP-B-No. 53-37810.
- Abrasion tests were performed on the surface of the rectangular test pieces as shown in FIG. 1, being polished as far as about 1 mm in depth.
- the test pieces were subjected to abrasion tests using an Ogoshi-type abrasion test machine with a FC25 counter material, in a lubricating-oil free, dry condition.
- the alloy has a good castability comparable to those of conventional alloys.
- the abrasion resistance of the alloy of the present invention is superior to that of the alloy of JP-B-No. 53-37810 and is comparable to that of 390 Alloy.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
Abstract
An aluminum alloy for abrasion resistant die castings comprising by weight, 6.0 to 9.0% Cu, 0.5 to 2.0% Mn, 1.6 to 3.0% Fe, 3% or less Mg, together with 13.5 to 20.0% Si, 0.5% or less Ni, an inevitable impurity of 0.3% or less Sn, and the remainder being Al, prepared by crystallizing out primary Si crystals of Si and Al-Fe-Mn-Si compounds and by forming a solid solution with Cu and Mg in the alloy's matrix.
Description
This invention relates to an aluminum alloy for abrasion resistant die casting. More particularly, it relates to an aluminum alloy with excellent abrasion resistance and mechanical properties.
Hypereutectic aluminum alloys containing, by weight, from 14 to 25% silicon have been widely used in sliding parts as die casting alloys having excellent abrasion resistance. Especially, 390 Alloy comprising by weight 16.0 to 18.0% Silicon(Si), 4.0 to 5.0% Copper(Cu), 0.45 to 0.65% Magnesium(Mg), 0.1% or less Zinc(Zn), 0.6 to 1.1% Iron(Fe), 0.1% or less Manganese(Mn), 0.02% or less Titanium(Ti), trace of Phosphorous(P), and the remainder being Aluminum(Al), is so highly resistant against abrasion that it is used as an aluminum engine block free from cast iron liners. The alloy disclosed in JP-B-No. 53-37810 (the term "JP-B" as used herein means an "examined Japanese patent publication") comprising by weight, 13.5 to 16.0% Si, 4.0 to 5.0% Cu, 0.5% or less Mg, 1.0% or less Zn, 1.3% or less Fe, 0.5% or less Mn, 0.05 to 0.1% P, 0.5% or less Nickel(Ni), 0.3% or less Tin(Sn), and the remainder being Al, is 390-Alloy based, in which the alloy's machinability is improved without considerably damaging its original abrasion resistance. The alloy is used in a broad field as housings of door closers, etc.
The alloy disclosed in JP-A-No. 60-2643 (the term "JP-A" as used herein means a published unexamined Japanese patent application) containing by weight, 5.0 to 22.5% Si, 5.5 to 10.5% Cu, 0.8 to 1.5% Fe, 0.85 to 1.5% Mg, 0.002 to 0.025% P, and the remainder being Al and inevitable impurities, is an aluminum alloy for die castings suitably used for sliding parts which work satisfactorily when used with either high- or low-viscosity lubricating oils.
The excellent abrasion resistances of the aforesaid 390 Alloy and the alloy disclosed in JP-B-No. 53-37810 have been attained by existing primary Si crystals. Therefore, an amount of Si is necessarily increased to improve abrasion resistance. Increasing the concentration of Si to 20 wt % or more, however, leads to higher casting temperature and brings about disadvantages such as shortening the mold life. Furthermore, increasing primary Si crystals leads to a lowering of machinability. It is therefore preferable to improve abrasion resistance without adding a large amount of Si.
The inventors have studied a solution for aforesaid problems and developed an aluminum alloy for abrasion resistant die casting comprising by weight, 6.0 to 9.0% Cu, 0.5 to 2.0% Mn, 1.6 to 3.0% Fe, 3% or less Mg, together with 13.5 to 20.0% Si, 0.5% or less Ni, inevitable impurities and the remainder being Al, with the hardness of the new alloy being increased by crystallizing out primary Si crystals and Al-Fe-Mn-Si compounds, and by forming a solid solution with Cu and Mg in the alloy's matrix.
FIG. 1 shows the test pieces prepared with the alloy of the present invention.
FIG. 2 shows micrographs, at 5,000 times magnification of the cast structures of the alloys; "a" is for the alloy of the present invention, "b" is for the 390 Alloy, and "c" is the alloy disclosed in JP-B-No. 53-37810.
FIG. 3 shows the results of planar analyses by EPMA (Electron Probe Micro Analysis) for primary Si crystals and Al-Fe-Mn-Si quaternary intermetallic compounds at 1,500 times magnification, wherein a is the SEM (Seanning Electron Micrograph) image, and b, c, d, and e show the results with Al-Kα, Fe-Kα, Mn-Kα and Si-Kα radiations, respectively.
The alloy composition of the present invention contains from 13.5 to 20.0% by weight of Si to give excellent castability and abrasion resistance. If the amount of Si is less than 13.5% by weight, the product would be deficient in primary Si crystals, and abrasion resistance would not be improved. If the addition is in excess of 20% by weight, the addition would leads to a rise in casting temperature, and the machinability of the alloy would therefore be adversely affected. The preferred range for Si is 15.2 to 17.5% by weight.
Copper forms a solid solution with Al to enhance the strength and improve the high temperature strength of the alloy. The addition of copper is desirably 5.9% by weight or more, however, addition in excess of 9.0% gives no apparent improvement in strength but adversely lowers the castability. Copper addition by weight is, therefore, desirably in the range from 6.0 to 9.0%, most preferably from 0.0 to 7.1%.
Addition of manganese leads to the formation of a massive Al-Fe-Mn-Si quaternary intermetallic compound having a hardness Hv of about 960. Though the hardness of the compound is lower than that of Si (Hv=1,300), it contributes to the improvement of abrasion resistance. Too high an amount of Mn addition, on the other hand, forms a sludge during dissolution which settles on the bottom of the crucible. The amount of Mn addition by weight, therefore, should be 2% or less, preferably from 0.5 to 2%, most preferably 1.1 to 1.7%.
Iron avoids adhesion to a metal mould and also forms an Al-Fe-Mn-Si intermetallic compound which improves abrasion resistance. Iron should be added in an amount of 1.6% by weight or more to sufficiently give the aforesaid intermetallic compound. Addition of Fe in excess, however, adversely affects mechanical properties. The Fe content is desirably less than 3.0% by weight. Most preferably Fe addition is from 1.7 to 2.8% by weight.
Magnesium addition increases mechanical strength and hardens the alloy per se. However, too large an addition of magnesium adversely affects melt fluidity, and brittleness results. An addition of 3% by weight or less of magnesium gives satisfactory effects. Preferably Mg addition is from 1.0 to 2.2% by weight.
Nickel addition not only increases high temperature strength but also hardness. However, addition decreases corrosion resistance. Nickel addition is, desirably, 0.5% by weight or less, more preferably 0.1% by weight or less.
Zinc addition of 1.0% or less by weight gives satisfactory results. Preferred Zn addition is 0.1% by weight or less.
Tin is present as an inevitable impurity, but its content should be less than 0.3%.
Phosphorus is effective to make fine Si crystals. Fine Si crystals give good machinability and also improve mechanical properties. An addition of less than 0.001% by weight of phosphorus is insufficient to give fine crystals. An addition of more than 0.1% by weight, however, has no effect on the primary crystal size of Si. The addition of P is therefrom maintained in the range from 0.001 to 0.1% by weight. The preferred range for P addition is from 0.05 to 0/1% by weight.
The present invention is hereinafter described in greater detail with reference to examples, which are not to be construed as limiting the scope thereof. Unless otherwise indicated, all parts, percents and ratios are by weight.
Characteristics of the alloy of the present invention, the conventional 390 Alloy, and the alloy disclosed in JP-B-No. 53-37810 were evaluated. The methods and the results of the experiments are given below.
The experiments were performed on test pieces shown in FIG. 1 having the alloy compositions as listed in Table 1. A 90-ton die casting machine was used for casting. Casting conditions were as follows: temperature of 720° to 730° C., casting pressure of 760 kgf/cm2, plunger tip speed of 1.35 to 1.40 m/sec, mold temperature of 120° to 140° C., and mold release time of 4 sec.
TABLE 1
__________________________________________________________________________
Alloy composition (wt %)
Alloy number
Si Cu Mg Zn Fe Mn Ni Sn Ti P Al
__________________________________________________________________________
1 13.0
4.04
1.57
0.33
1.72
1.41
0.06
0.01
-- 0.06
Balance
Comparison
2 14.6
5.40
1.44
0.28
1.78
1.44
0.08
0.02
-- 0.07
" "
3 15.2
5.99
1.86
0.34
1.79
1.45
0.06
0.02
-- 0.08
" Invention
4 15.0
6.70
1.25
0.38
1.82
1.46
0.07
0.02
-- 0.07
" "
5 15.5
6.79
3.04
0.40
1.77
1.48
0.08
0.02
-- 0.07
" Comparison
6 15.4
7.52
1.98
0.39
1.91
1.44
0.06
0.02
-- 0.08
" Invention
7 15.3
10.02
1.16
0.36
1.88
1.43
0.07
0.01
-- 0.07
" Comparison
8 17.5
7.03
1.02
0.12
1.98
1.15
0.03
Tr -- 0.06
" Invention
9 15.6
7.12
1.24
0.39
0.68
0.41
0.08
0.02
-- 0.05
" Comparison
10 15.2
7.02
2.20
0.33
2.71
1.62
0.07
0.01
-- 0.06
" Invention
390 16.8
4.50
0.38
0.08
1.06
0.08
Tr Tr 0.02
Tr " Reference
JP-B-53-37810
14.6
4.85
0.44
0.29
0.72
0.33
0.08
002
-- 0.07
" "
__________________________________________________________________________
Each alloy composition of the present invention showed excellent castability free from run deficiency, scuffing, and seizure. When the Cu content is 10%, the run is more or less damaged.
Casting structures for the die cast alloy of the present invention, 390 Alloy, and the alloy disclosed in JP-B-No. 53-37810 are given in FIG. 2. The test pieces were etched with an aqueous 5% HF solution. The casting structures of 390 Alloy and the alloy of JP-B-No. 53-37810 comprise primary Si crystals, dendritic and eutectic crystals of Si, and intermetallic compounds such as CuAl2 and Mg2 Si. In 390 Alloy, dark gray granules are the primary Si crystals. The large granules deteriorate the machinability. In the alloy of JP-B-No. 53-37810, the granules are reduced in size so that the machinability is improved, however, the amount of the primary Si granules is decreased so that the hardness is lowered. The cast structure of the alloy of the present invention exhibits additional crystal deposition of Al-Si-Fe-Mn quaternary intermetallic compound. Light gray granules observed in the micrograph correspond to above crystals. The hardness, Hv, for the intermetallic compound is about 960, and is lower than that of Si (Hv=1,300), however, the compound highly contributes to improved abrasion resistance. Dendritic crystals are clearly observed as compared with 390 Alloy and the alloy of JP-B-No. 53-37810 since the Cu concentration of the former is larger than the latter two. The Cu concentration in the central part of the dendritic crystal measured by EPMA (Electron Probe Micro Analysis) gave about 1.1% and 1.0% by weight for 390 Alloy and the alloy of JP-B-No. 53-37810, respectively, in contrast to 1.4 to 1.8% by weight for the alloys of the present invention. Copper is therefore assumed to contribute to solid-solution strengthening.
FIG. 3 shows the EPMA result for the Al-Si-Fe-Mn quaternary intermetallic compound. The Scanning Electron Micrograph given in FIG. 3a reveals a mass nearly hexagonal in shape to be present at a lower left side thereof. EPMA analysis using Al-Kα radiation (FIG. 3b) indicates that the massive part is low in Al, but is high in Fe and Mn as observed in analyses using Fe-Kα (FIG. 3c) and Mn-Kα (FIG. 3d). The analysis using Si-Kα (FIG. 3e), shows that the massive part is slightly low in Si. The massive part is therefore identified as an Al-Si-Fe-Mn quaternary intermetallic compound. FIG. 3d indicates an extremely high Si concentration at the upper right of the micrograph.
Test pieces shown in FIG. 1 having the alloy compositions as listed in Table 1 were subjected to measurements of tensile strength, 0.2% yield strength, elongation, and hardness. The results are given in Table 2. The results are given with the average value of N(number of samples)=5.
The test pieces shown in FIG. 1 were subjected to tensile test at room temperature using a 10-ton tensile tester. The speed was 5 mm/sec. In both the tensile strength and the 0.2% yield strength, the higher the Cu content, the larger the result obtained. Both values keep approximately constant values at Cu contents of 6 to 7% or more. The tensile strength and the 0.2% yield strength of the alloy of the present invention are approximately 10% higher and 20% higher respectively than that of 330 Alloy or the alloy of JP-B-No. 53-37810. Elongation increases more or less with the addition of Mn, and is low when the Cu content is high. The elongation is the least for the alloy containing about 3% by weight of Cu.
Hardness was measured on the surface of a rectangular test piece as shown in FIG. 1, being polished as far as about 1 mm in depth. A Rockwell hardness testing machine was employed and the measurement was performed based on the B scale. It was harder for a higher Cu content, and reached approximately a constant value in the range from 6 to 9% by weight of Cu. The hardness of the alloy of the present invention is about 10% higher than the conventional 390 Alloy, and about 20% higher than the alloy of JP-B-No. 53-37810.
Abrasion tests were performed on the surface of the rectangular test pieces as shown in FIG. 1, being polished as far as about 1 mm in depth. The test pieces were subjected to abrasion tests using an Ogoshi-type abrasion test machine with a FC25 counter material, in a lubricating-oil free, dry condition.
The abrasion test results are given in Table 3. The results are given with an average value of N=5. Abrasion resistances are improved for those alloys having additional Mn or Fe. Abrasion resistance is higher at any velocity with a higher Cu content, and approaches approximately a constant value at 6 to 7% by weight of Cu, showing a tendency similar to those obtained in the tensile and hardness tests.
TABLE 2
__________________________________________________________________________
Mechanical Properties
Tensile
0.2% yield
Elongation to
Strength
Strength
Fracture
Hardness
Alloy number
(kgf/mm.sup.2)
(kgf/mm.sup.2)
(%) (H.sub.R E)
__________________________________________________________________________
1 27.8 22.7 0.65 70.3 Comparison
2 29.0 24.2 0.48 75.5 "
3 30.5 26.2 0.31 83.5 Invention
4 31.4 28.1 0.30 84.9 "
5 31.0 28.3 0.29 85.2 Comparison
6 29.7 29.2 0.20 86.7 Invention
7 31.2 28.5 0.26 84.4 Comparison
8 31.0 30.1 0.38 83.7 Invention
9 29.4 27.8 0.40 80.6 Comparison
10 31.2 30.0 0.31 88.3 Invention
390 29.2 24.9 0.42 75.0 Reference
JP-B-53-37810
28.2 23.9 0.38 71.9 Reference
__________________________________________________________________________
TABLE 3
__________________________________________________________________________
Specific Abrasion × 10.sup.-7 mm.sup.2 /kg
Alloy number
0.96 m/sec
1.96 m/sec
2.86 m/sec
4.36 m/sec
__________________________________________________________________________
1 31.5 30.2 31.2 34.0 Comparison
2 24.0 29.5 27.0 32.8 "
3 22.8 24.0 23.5 26.2 Invention
4 21.9 23.3 24.0 26.0 "
5 21.0 23.8 19.8 24.8 Comparison
6 23.0 23.5 19.4 22.7 Invention
7 21.5 20.8 22.4 24.0 Comparison
8 21.7 21.6 21.9 23.0 Invention
9 25.1 24.2 27.8 28.6 Comparison
10 19.3 18.7 19.4 21.8 Invention
390 23.6 25.3 23.8 26.1 Reference
JP-A-53-37810
28.5 28.2 29.6 31.2 Reference
__________________________________________________________________________
The above results are summarized as follows.
(1) The alloy has a good castability comparable to those of conventional alloys.
(2) The Cu solubility in the dendritic crystals is higher than in the conventional alloys wherein strength may be increased by solid-solution strengthening.
(3) Tensile strength, 0.2% yield strength, and hardness of the present alloy are all superior to those of the conventional 390 Alloy or to those of the alloy of JP-B-No. 53-37810.
(4) The abrasion resistance of the alloy of the present invention is superior to that of the alloy of JP-B-No. 53-37810 and is comparable to that of 390 Alloy.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
Claims (4)
1. An aluminum alloy for abrasion resistant die casts consisting essentially of by weight, 6.0 to 9.0% Cu, 0.5 to 2.0% Mn, 1.6 to 3.0% Fe, 3% or less Mg, together with 13.5 to 20.0% Si, 0.5% or less Ni, inevitable impurities and the remainder being Al, prepared by crystallizing out primary Si crystals of Si and Al-Fe-Mn-Si compounds, and by forming a solid solution with Cu and Mg in the alloy's matrix.
2. An aluminum alloy according to claim 1, wherein the inevitable impurities comprises 1.0% or less Zn and 0.3% or less Sn.
3. An aluminum alloy according to claim 1, which further comprises 0.001 to 0.1% P.
4. An aluminum alloy for abrasion resistant die casts consisting essentially of by weight, 6.0 to 7.1% Cu, 1.1 to 1.7% Mn, 1.7 to 2.8% Fe, 1.0 to 2.2% Mg, 0.4% or less Zn, and 0.05 to 0.1% P, together with 15.2 to 17.5% Si, 0.1% or less Ni, an impurity of 0.3% or less Sn, and the remainder being Al, prepared by crystallizing out primary Si crystals of Si and Al-Fe-Mn-Si compounds, and by forming a solid solution with Cu and Mg in the alloy's matrix.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62-188744 | 1987-07-30 | ||
| JP62188744A JP2630401B2 (en) | 1987-07-30 | 1987-07-30 | Aluminum alloy for wear-resistant die-casting |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US4919736A true US4919736A (en) | 1990-04-24 |
Family
ID=16229012
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US07/226,011 Expired - Lifetime US4919736A (en) | 1987-07-30 | 1988-07-29 | Aluminum alloy for abrasion resistant die castings |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4919736A (en) |
| JP (1) | JP2630401B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5329382A (en) * | 1991-03-04 | 1994-07-12 | Eastman Kodak Company | Image scanner |
| EP1253210A1 (en) * | 2001-03-28 | 2002-10-30 | Honda Giken Kogyo Kabushiki Kaisha | Heat resistant Al die cast material |
| US20070193663A1 (en) * | 2004-03-23 | 2007-08-23 | Nippon Light Metal Company, Ltd. | Aluminum alloy for casting, having high rigidity and low liner expansion coefficiant |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03111531A (en) * | 1989-09-25 | 1991-05-13 | Riken Corp | Rotor made of aluminum alloy |
| JP3718147B2 (en) * | 2001-07-31 | 2005-11-16 | 株式会社日立製作所 | Turbocharger for internal combustion engines |
| CN108715957A (en) * | 2018-05-31 | 2018-10-30 | 益阳仪纬科技有限公司 | A kind of automotive transmission shell high-strength aluminum alloy composite material and its preparation process |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4648918A (en) * | 1984-03-02 | 1987-03-10 | Kabushiki Kaisha Kobe Seiko Sho | Abrasion resistant aluminum alloy |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5289512A (en) * | 1976-01-22 | 1977-07-27 | Mitsubishi Metal Corp | Al alloy for parts in contact with magnetic tape |
| JPS5858917B2 (en) * | 1976-09-21 | 1983-12-27 | 株式会社東芝 | Control device for commutatorless motor |
| JPS602643A (en) * | 1983-06-21 | 1985-01-08 | Nippon Light Metal Co Ltd | Die casting aluminum alloy with superior wear resistance |
-
1987
- 1987-07-30 JP JP62188744A patent/JP2630401B2/en not_active Expired - Lifetime
-
1988
- 1988-07-29 US US07/226,011 patent/US4919736A/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4648918A (en) * | 1984-03-02 | 1987-03-10 | Kabushiki Kaisha Kobe Seiko Sho | Abrasion resistant aluminum alloy |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5329382A (en) * | 1991-03-04 | 1994-07-12 | Eastman Kodak Company | Image scanner |
| EP1253210A1 (en) * | 2001-03-28 | 2002-10-30 | Honda Giken Kogyo Kabushiki Kaisha | Heat resistant Al die cast material |
| US20070193663A1 (en) * | 2004-03-23 | 2007-08-23 | Nippon Light Metal Company, Ltd. | Aluminum alloy for casting, having high rigidity and low liner expansion coefficiant |
| US20100296964A1 (en) * | 2004-03-23 | 2010-11-25 | Nippon Light Metal Company, Ltd. | Aluminum alloy for casting having high rigidity and low linear expansion coefficient |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2630401B2 (en) | 1997-07-16 |
| JPS6436743A (en) | 1989-02-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100199362B1 (en) | Aluminum alloy for die casting and ball joints using the same | |
| JP3354098B2 (en) | Magnesium alloy with excellent high temperature properties and die castability | |
| EP3121302B1 (en) | Aluminum alloy for die casting, and die-cast aluminum alloy using same | |
| JP5355320B2 (en) | Aluminum alloy casting member and manufacturing method thereof | |
| CN105483465B (en) | A kind of die casting Al-Si-Mg cast aluminium alloy golds and preparation method thereof | |
| US4169728A (en) | Corrosion resistant bright aluminum alloy for die-casting | |
| MX2007001008A (en) | An al-si-mg-zn-cu alloy for aerospace and automotive castings. | |
| GB2127039A (en) | Fine-grained copper-nickel-tin alloys | |
| EP1241276A1 (en) | Creep-resistant magnesium alloy | |
| US20030084968A1 (en) | High strength creep resistant magnesium alloys | |
| US4919736A (en) | Aluminum alloy for abrasion resistant die castings | |
| WO1996025529A1 (en) | Creep resistant magnesium alloys for die casting | |
| US3567436A (en) | Compression resistant zinc base alloy | |
| US7169240B2 (en) | Creep resistant magnesium alloys with improved castability | |
| JP2003027169A (en) | Aluminum alloy and cast aluminum alloy | |
| KR920001628B1 (en) | High strength cast zinc alloys and dies and die-cast products of this alloy | |
| EP0899349A1 (en) | Heat-resistant zinc alloy and molded article thereof | |
| US3718460A (en) | Mg-Al-Si ALLOY | |
| US4242133A (en) | Copper base alloy containing manganese | |
| WO1994004712A1 (en) | Lead-free copper base alloys | |
| JPH0649572A (en) | High strength zinc alloy and zinc alloy die casting parts for die casting | |
| JPH0448856B2 (en) | ||
| KR100343309B1 (en) | Hot chamber castable zinc alloy | |
| GB2066853A (en) | Zinc-based alloys | |
| US1885429A (en) | Magnesium base alloys |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: RYOBI LIMITED, 762, MESAKI-CHO, FUCHU-SHI, HIROSHI Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:NISHI, NAOMI;TAKAHASHI, YOSUKE;REEL/FRAME:004913/0083 Effective date: 19880722 Owner name: RYOBI LIMITED,JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NISHI, NAOMI;TAKAHASHI, YOSUKE;REEL/FRAME:004913/0083 Effective date: 19880722 |
|
| STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
| FEPP | Fee payment procedure |
Free format text: PAT HLDR NO LONGER CLAIMS SMALL ENT STAT AS SMALL BUSINESS (ORIGINAL EVENT CODE: LSM2); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
| FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
| FEPP | Fee payment procedure |
Free format text: PAT HOLDER CLAIMS SMALL ENTITY STATUS - SMALL BUSINESS (ORIGINAL EVENT CODE: SM02); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
| FPAY | Fee payment |
Year of fee payment: 4 |
|
| FEPP | Fee payment procedure |
Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
| FPAY | Fee payment |
Year of fee payment: 8 |
|
| FPAY | Fee payment |
Year of fee payment: 12 |